1. Field of the Invention
The present invention relates to an impact sensor and, more particularly, to an impact sensor for detecting, when, for example, a car accident occurs.
2. Description of the Related Art
Acceleration sensors of various types have been used as impact sensors. Such acceleration sensors have been used, for example, to detect an impact applied to a car when the car is involved in an accident. This is done, for example, to unlock the doors of the car making it easier to save persons trapped in the car.
However, conventional acceleration sensors can detect an impact in only one direction (plane). For this reason, if impacts in all directions are to be detected, acceleration sensors must be disposed in three axial directions intersecting at right angles to each other. When three acceleration sensors are used, the size of the impact sensor is increased as are the manufacturing costs. Additionally, there is a directional aspect in mounting the impact sensor.